English Translation

Affan told us: Mahdi told us: Wasil al-Ahdab told us, from Abu Wa'il, from Abdullah ibn Mas'ud, who said: I said, "O Messenger of Allah, which sin is greatest?" He said, "That you set up a rival to Allah while He created you." I said, "O Messenger of Allah, then what?" He said, "Then that you commit adultery with your neighbor's wife."